While the keyboard of WP7 is excellent indeed I do not understand why the four arrows to move the cursor are missing: if you mistyped a letter in the middle of a word putting the cursor ahead of the letter you want to replace is a cumbersome process to say the least.
Another thing I do not understand is why when you enter PW to unlock the phone the number syou push are highlighted; the first release of the the Tablet OS, in 2001/2002 had this issue and MS corrected right away. It is a serious security oversight.